In the field of interior furniture, it is known to use snap hinges which are suitable for the rotation of a closure element about a substantially horizontal or inclined axis, such as for example snap hinges used to open and close doors on cabinets arranged inside caravans or the like.
Known snap hinges comprise a first articulated quadrilateral and a second articulated quadrilateral, which share a first lever and a second lever and have as their base element respectively a plate for coupling to a fixed element of a piece of furniture or the like and a plate for fixing to the closure element.
Further, known snap hinges comprise a spring which acts between two mutually opposite points of one of the two articulated quadrilaterals.
Each of the two articulated quadrilaterals is constituted by the first and second levers, by an arm and by a base element, respectively the coupling plate or the fixing plate, which are mutually articulated. The spring acts between a contact and articulation point on the first lever and a contact and articulation point on the second lever.
Again with reference to pieces of furniture such as cabinets for the interior furnishing of caravans or the like, the coupling plate is anchored to the wall that delimits in an upper region the cabinet and on the surface that faces the internal compartment thereof.
The fixing blade is anchored to the door on the surface that is designed to face, in the closed configuration of the door, the compartment of the cabinet.
The coupling plate and the fixing plate are fixed generally by way of threaded means such as screws.
In the open configuration, the spring of the snap hinge acts in contrast to the weight force of the door and therefore has a supporting function for said door.
In the closure configuration, the elastic action applied by the spring is suitable to keep the door in a position for closing the compartment of the cabinet.
The above described snap hinges are not free from drawbacks, including the fact that in the open configuration the spring that acts in opposition to the weight force of the door is subject to partial compression and does not ensure the maximum opening of said door with respect to the cabinet, consequently hindering user access to the content of the compartment.
Also with particular reference to the application of said hinges to doors and cabinets for the interior furnishing of caravans or the like, a further drawback is that the elastic action applied by the spring and suitable to keep the door in a position for closing the compartment of the cabinet is not such as to prevent the accidental opening of the door, for example, when the caravan or the like is moving and on bends, with the consequent escape of the contents from the cabinet.
A second known type of snap hinge comprises two articulated quadrilaterals and has two springs which are arranged in series or in parallel to each other and, with particular reference to cabinets for caravans or the like, provide a more stable and safe support of the door, both in the open configuration and in the closed configuration, with respect to hinges that comprise a single spring.
If the springs are arranged parallel to each other, they act between two mutually opposite points of a same articulated quadrilateral, whereas if they are arranged in series they act between two mutually opposite points of a respective articulated quadrilateral.
In these last hinges, the plate for coupling to the fixed structure of a piece of furniture or the like is bridge-shaped.
With particular reference again to cabinets for caravans or the like, the bridge-shaped coupling plate is suitable for the anchoring of the hinge to a supporting element which is rigidly fixed to the wall that delimits in an upper region the cabinet and to the inside of the compartment. Said bridge-shaped coupling plate is arranged, in the closed configuration of the hinge, on a plane of arrangement which is substantially perpendicular to the door.
Said hinges are not free from drawbacks, the first of which is high structural complexity due to the particular type of anchoring by means of the coupling plate, with consequent significant production costs.
Moreover, in order to anchor the hinge to the cabinet or the like it is necessary to use an additional supporting element, which is fixed to one of the walls of said cabinet, thus limiting the possibilities of use of the hinge.